Method for activation of helper T cell and composition for use in the method

ABSTRACT

Disclosed are: a method for activating a helper T cell, which comprises the step of adding a WT1 peptide to an antigen-presenting cell to activate the helper T cell, wherein the WT1 peptide is capable of binding to any one selected from an HLA-DRB1*1501 molecule, an HLA-DPB1*0901 molecule and an HLA-DPB1*0501 molecule; a composition for use in the method; a therapeutic and/or prophylactic method for cancer by activating a helper T cell; a pharmaceutical composition for use in the therapeutic and/or prophylactic method; and others.

TECHNICAL FIELD

The present invention relates to a method for the activation of a helper T cell, comprising adding a WT1 peptide to an antigen-presenting cell, and thereby activating the helper T cell, wherein the WT1 peptide has an ability to any one of an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule and HLA-DPB1*0501 molecule and a composition for the same, a pharmaceutical composition for the treatment and/or prevention of a cancer by activating a helper T cell and the like.

BACKGROUND

WT1 gene (Wilms' tumor 1 gene) was identified as a gene responsible for Wilms tumor which is a renal cancer in children (Non-Patent Documents 1 and 2). WT1 is a transcription factor having a zinc finger structure. At the beginning, the WT1 gene was considered to be a tumor suppressor gene. However, subsequent studies (Non-Patent Documents 3, 4, 5 and 6) showed that the WT1 gene rather functions as an oncogene in hematopoietic tumors and solid cancers.

It was shown that a WT1 peptide-specific T-lymphocyte (CTL) can be induced by in vitro stimulating a peripheral blood mononuclear cell with a WT1 peptide, and such a CTL damages a cancer cell such as a hematopoietic tumor cell and solid cancer cell which endogenously expresses WT1. The CTL recognizes the WT1 peptide as the form of the complex in which the WT1 peptide binds to an MHC class I molecule. Therefore, such a WT1 peptide is different depending on the subtypes of MHC class I (Patent Document 1, Non-Patent Document 7, and Patent Documents 2, 3 and 4).

The existence of a helper T cell specific for an cancer antigen is important to induce a CTL effectively (Non-Patent Document 8). The helper T cell is induced and activated by the recognition of a complex of an MHC class II molecule and an antigen peptide on an antigen-presenting cell. The activated helper T cell produces a cytokine such as IL-2, IL-4, IL-5, IL-6 or interferon to help the growth, differentiation or maturation of a B cell. The activated helper T cell also has a function to facilitate the growth, differentiation or maturation of other T cell subsets (for example, Tc and TD cell). Thus, the activated helper T cell has a function to activate an immune system by facilitating the growth or activation of a B cell or T cell. Therefore, enhancing a function of a helper T cell through an MHC class II-binding antigen peptide (a helper peptide) in a cancer immunotherapy to increase the effect of a cancer vaccine is considered to be useful (Non-Patent Document 9). Only a peptide binding to an HLA-DRB1*0401 molecule (Non-Patent Document 10), a peptide binding to an HLA-DRB1*0405 molecule and a peptide binding to an HLA-DRB1*1502 molecule (Patent Document 5) were found as a helper peptide of WT1 to date. Therefore, there is a need to find peptides each biding to an HLA-DRB1*1501, HLA-DPB1*0901 or HLA-DPB1*0501 molecule.

Furthermore, it was shown that among the helper peptides, there is a promiscuous helper peptide which can bind to multiple MHC class II molecules, and induce helper T cells (Non-Patent Documents 11 and 12). However, it was very difficult to identify a promiscuous helper peptide which binds to three or more types of MHC class II molecules and exerts a sufficient effect.

-   Patent Document 1: WO 2003/106682 -   Patent Document 2: WO 2005/095598 -   Patent Document 3: WO 2007/097358 -   Patent Document 4: International Patent Application No.     PCT/JP2007/074146 -   Patent Document 5: WO 2005/045027 -   Non-Patent Document 1: Daniel A. Haber et al., Cell. 1990 Jun. 29;     61(7):1257-69. -   Non-Patent Document 2: Call K M et al., Cell. 1990 Feb. 9;     60(3):509-20. -   Non-Patent Document 3: Menke A L et al., Int Rev Cytol. 1998;     181:151-212. Review. -   Non-Patent Document 4: Yamagami T et al., Blood. 1996 Apr. 1;     87(7):2878-84. -   Non-Patent Document 5: Inoue K et al., Blood. 1998 Apr. 15;     91(8):2969-76. -   Non-Patent Document 6: Tsuboi A et al., Leuk Res. 1999 May;     23(5):499-505. -   Non-Patent Document 7: Oka Y et al., Immunogenetics. 2000 February;     51(2):99-107. -   Non-Patent Document 8: Gao F G et al., Cancer Res. 2002 Nov. 15;     62(22):6438-41. -   Non-Patent Document 9: Zeng G, J Immunother. 2001 May; 24(3):195-204 -   Non-Patent Document 10: Knights A J et al., Cancer Immunol     Immunother. 2002 July; 51(5):271-81. -   Non-Patent Document 11: Sotiriadou R et al., Br J Cancer. 2001 Nov.     16; 85(10):1527-34. -   Non-Patent Document 12: Hural J A et al., J Immunol. 2002 Jul. 1;     169(1):557-65.

DISCLOSURE OF INVENTION Problems to be Solved by the Invention

The problems to be solved by the present invention are to provide to a method for the activation of a helper T cell with a WT1 peptide which has an ability to bind to an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule or HLA-DPB1*0501 molecule and a composition for the same, as well as a pharmaceutical composition for the treatment and/or prevention of a cancer by activating a helper T cell and the like.

Means to Solve the Problems

As a result of intensive studies in view of the situation as described above, the present inventor has found that among WT1 peptides which bind to an HLA-DRB1*0405 molecule and HLA-DRB1*1502 molecule, a WT1 peptide having an amino acid sequence: Lys Arg Tyr Phe Lys Leu Ser His Leu Gln Met His Ser Arg Lys His (SEQ ID NO: 2) also binds to an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule and HLA-DPB1*0501 molecule. Thus, the present invention has been completed.

The present invention provides:

(1) a method for the activation of a helper T cell, comprising adding a WT1 peptide to an antigen-presenting cell, and thereby activating the helper T cell, wherein the WT1 peptide has an ability to bind to any one of an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule and HLA-DPB1*0501 molecule;

(2) the method according to (1), wherein the WT1 peptide has an ability to bind to at least two of an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule and HLA-DPB1*0501 molecule;

(3) the method according to (1) or (2), wherein the WT1 peptide further has an ability to bind to an HLA-DRB1*0405 molecule and/or HLA-DRB1*1502 molecule;

(4) the method according to any one of (1)-(3), wherein the WT1 peptide has an ability to bind to an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule, HLA-DPB1*0501 molecule, HLA-DRB1*0405 molecule and HLA-DRB1*1502 molecule;

(5) the method according to any one of (1)-(4), wherein the WT1 peptide is a peptide comprising an amino acid sequence: Lys Arg Tyr Phe Lys Leu Ser His Leu Gln Net His Ser Arg Lys His (SEQ ID No: 2);

(6) the method according to any one of (1)-(5), wherein the addition of the WT1 peptide to the antigen-presenting cell is practiced by the addition of the WT1 peptide, the addition of n expression vector comprising the polynucleotide encoding the WT1 peptide or the addition of a cell including the expression vector;

(7) a composition for activating a helper T cell by the addition of a WT1 peptide to an antigen-presenting cell, comprising the WT1 peptide, wherein the WT1 peptide has an ability to bind to any one of an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule and HLA-DPB1*0501 molecule;

(8) a method for the treatment or prevention of a cancer in a subject, comprising adding a WT1 peptide to an antigen-presenting cell, and thereby activating a helper T cell, wherein the WT1 peptide has an ability to bind to any one of an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule and HLA-DPB1*0501 molecule;

(9) a pharmaceutical composition for the treatment or prevention of a cancer by activating a helper T cell by the addition of a WT1 peptide to an antigen-presenting cell, comprising the WT1 peptide, wherein the WT1 peptide has an ability to bind to any one of an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule and HLA-DPB1*0501 molecule;

(10) an antibody binding specifically to a WT1 peptide, wherein the WT1 peptide has an ability to bind to any one of an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule and HLA-DPB1*0501 molecule;

(11) a method for the determination of the presence or amount of a WT1 peptide in any one of an HLA-DRB1*1501-positive, HLA-DPB1*0901-positive and HLA-DPB1*0501-positive subject, comprising:

(a) reacting an anti-WT1 antibody with a sample from the subject; and

(b) determining the presence or amount of the anti-WT1 antibody binding specifically to the WT1 peptide contained in the sample;

(12) a method for the treatment or prevention of a cancer, comprising adding a WT1 peptide to an antigen-presenting cell, and thereby activating a helper T cell, and administering the activated helper T cell to a subject, wherein the WT1 peptide has an ability to bind to an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule or HLA-DPB1*0501 molecule;

(13) a pharmaceutical composition for the treatment or prevention of a cancer, comprising a helper T cell activated with a WT1 peptide, wherein the WT1 peptide has an ability to bind to any one of an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule and HLA-DPB1*0501 molecule;

(14) a method for the determination of the presence or amount of a WT1-specific helper T cell in any one of an HLA-DRB1*1501-positive, HLA-DPB1*0901-positive and HLA-DPB1*0501-positive subject, comprising:

(a) reacting a complex of a WT1 peptide and an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule or HLA-DPB1*0501 molecule with a sample from the subject; and

(b) determining the presence or amount of a helper T cell recognizing the complex contained in the sample; and

(15) a method for the determination of the presence or amount of a WT1-specific helper T cell in an HLA-DRB1*1501-positive, HLA-DPB1*0901-positive, HLA-DPB1*0501-positive, HLA-DRB1*0405-positive or HLA-DRB1*1502-positive subject, comprising:

(a) stimulating a peripheral blood mononuclear cell, invasive lymphocyte, tumor cell, cell in ascitic fluid, cell in pleural fluid, cell in cerebrospinal fluid, bone marrow cell or lymph node cell with a WT1 peptide; and

(b) determining the production of a cytokine or the reaction of the helper T cell,

wherein a presence or an increase in the amount of the production of the cytokine or the reaction of the helper T cell indicates the presence or amount of the WT1-specific helper T cell.

Effects of the Invention

The present invention provides a method for the activation of a helper T cell with a WT1 peptide which binds to an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule, HLA-DPB1*0501 molecule, HLA-DRB1*0405 molecule, and HLA-DRB1*1502 molecule and a composition for the same, as well as a pharmaceutical composition for the treatment and/or prevention of a cancer by activating a helper T cell, and the like. Therefore, it is possible to activate in vivo and in vitro a helper T cell in the subject having any of such MHC class II molecules, treat and prevent a cancer and the like. Because about 90% of Japanese people are covered by the five types of MHC class II subclasses, helper T cells can be activated to treat and/or prevent a cancer in a very wide range of subjects.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a graph which represents the amount of IFN-γ produced by TA28.1 cell. In the figure, a longitudinal axe represents concentration of IFN-γ (pg/ml). The graphs correspond to “the case of culturing peripheral blood mononuclear cells from an HLA-DRB1*1501-positive subject in the absence of the WT1 peptide”, “the case of culturing TA28.1 cells in the presence of the WT1 peptide (black)”, “the case of culturing peripheral blood mononuclear cells from an HLA-DRB1*1501-negative subject in the absence of the WT1 peptide”, “the case of culturing peripheral blood mononuclear cells from an HLA-DRB1*1501-negative subject in the presence of the WT1 peptide” starting from the left, respectively.

FIG. 2 is a graph which represents the amounts of IFN-γ, IL-4 and IL-10 produced by TA28.1 cell. In the figure, a longitudinal axe represents concentration (pg/ml). The graphs correspond the values of IFN-γ, IL-4 and IL-10 starting from the left.

FIG. 3 is a graph which represents the amounts of IFN-γ, IL-4 and IL-10 produced by E15.2 cell. In the figure, a longitudinal axe represents concentration (pg/ml). The graphs correspond to the values of IFN-γ, IL-4 and IL-10 starting from the left.

FIG. 4 represents the productions of IFN-γ and IL-17 by HLA-DPB1*0501/*0501-positive mononuclear cells. In the figure, a horizontal axe represents IFN-γ, and a longitudinal axe represents IL-17. FIG. 4a represents the cells without stimulating with the WT1 peptide, and FIG. 4b represents the cells stimulated with the WT1 peptide.

FIG. 5 is a graph which represents the growth of TA28.1 cells. In the figure, a longitudinal axe represents cpm (×10⁴). The graphs correspond to “the case of coculturing TA28.1 cells with peripheral blood mononuclear cells without pulsing with a WT1 peptide”, “the case of coculturing TA28.1 cells with peripheral blood mononuclear cells pulsed with a WT1 peptide (black)”, “the case of culturing TA28.1 cells with peripheral blood mononuclear cells pulsed with a WT1 peptide in the presence of an anti-MHC class I antibody”, “the case of coculturing TA28.1 cells with peripheral blood mononuclear cells pulsed with a WT1 peptide in the presence of an anti-HLA-DR antibody (shaded)”, “the case of coculturing TA28.1 cells with peripheral blood mononuclear cells pulsed with a WT1 peptide in the presence of an anti-HLA-DQ antibody”, “the case of coculturing TA28.1 cells with peripheral blood mononuclear cells pulsed with a WT1 peptide in the presence of an anti-HLA-Dantibody” starting from the left, respectively.

FIG. 6 is a graph which represents the growth of E15.2 cells. In the figure, a longitudinal axe represents cpm (×10⁴). The graphs correspond to “the case of coculturing E15.2 cells with peripheral blood mononuclear cells from an HLA-DPB1*0901-positive subject without pulsing with a WT1 peptide”, “the case of coculturing E15.2 cells with peripheral blood mononuclear cells from an HLA-DPB1*0901-positive subject pulsed with a WT1 peptide (black)”, “the cases of coculturing E15.2 cells with peripheral blood mononuclear cells from an HLA-DPB1*0901-negative subject without pulsing with a WT1 peptide”, “the case of coculturing E15.2 cells with peripheral blood mononuclear cells from an HLA-DPB1*0901-negative subject pulsed with a WT1 peptide” starting from the left, respectively.

FIG. 7 is a graph which represents the growth of E15.2 cells. In the figure, a longitudinal axe represents cpm. The graphs correspond to “the case of coculturing E15.2 cells with peripheral blood mononuclear cells without pulsing with a WT1 peptide”, “the case of coculturing E15.2 cells with peripheral blood mononuclear cells pulsed with a WT1 peptide (black)”, “the case of coculturing E15.2 cells with peripheral blood mononuclear cells pulsed with a WT1 peptide in the presence of an anti-MHC class I antibody”, “the case of coculturing E15.2 cells with peripheral blood mononuclear cells pulsed with a WT1 peptide in the presence of an anti-HLA-DR antibody”, “the case of coculturing E15.2 cells with peripheral blood mononuclear cells pulsed with a WT1 peptide in the presence of an anti-HLA-DQ antibody”, and “the case of coculturing E15.2 cells with peripheral blood mononuclear cells pulsed with a WT1 peptide in the presence of an anti-HLA-DP antibody (shaded)” starting from the left, respectively.

FIG. 8 is a graph which represents the growth of HLA-DPB1*0501/*0501-positive mononuclear cells. In the figure, a longitudinal axe represents cpm. The graphs correspond to “the case without stimulation with a WT1 peptide” and “the case with stimulation with a WT1 peptide” starting from the left, respectively.

FIG. 9 represents that the growth of HLA-DPB1*0501/*0501-positive mononuclear cells is suppressed by anti-HLA-DP antibodies. In the figure, a longitudinal axe represents cpm. The graphs correspond to “the case without stimulation with a WT1 peptide”, “the case with stimulation with a control peptide from HIV”, “the case with stimulation with a WT1 peptide”, “the case with stimulation with a WT1 peptide in the presence of an anti-HLA-DR antibody”, “the case with stimulation with a WT1 peptide in the presence of an anti-HLA-DQ antibody” and “the case with stimulation with a WT1 peptide in the presence of an anti-HLA-Dantibody” starting from the left, respectively.

FIG. 10 is a graph which represents the growth of E15.2 cell in the cases of using various concentration of a WT1 peptide. In the figure, a longitudinal axe represents cpm (×10⁴), and a horizontal axe represents the concentration of the WT1 peptide.

BEST MODE FOR CARRYING OUT THE INVENTION

In one aspect, the present invention relates to a method for the activation of a helper T cell, comprising adding a WT1 peptide to an antigen-presenting cell, and thereby activating the helper T cell, wherein the WT1 peptide has an ability to bind to any one of an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule and HLA-DPB1*0501 molecule. In the present invention, the WT1 peptide refers a peptide consisting of a part of the amino acid sequence of human WT1 protein shown in SEQ ID No: 1, a peptide which has a substitution, modification, or deletion of one to several amino acids in the amino acid sequence, and has an ability to bind to any one of an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule and HLA-DPB1*0501 molecule, or a peptide in which various substances such as an amino acid, a peptide or an analog thereof may be attached at the N-terminus and/or the C-terminus of the peptide. The substance can be processed, for example, by an enzyme in a living body or through a process such as intracellular processing, and finally the WT1 peptide becomes the form which can bind to any one of an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule and HLA-DPB1*0501 molecule. The substance may be a substance that modulates the solubility of the WT1 peptide of the present invention, or increases its stability (resistance to protease, etc.). Alternatively, it may be a substance that delivers the WT1 peptide of the present invention specifically, for example, to a given tissue or organ, or increases the efficiency of uptake by an antigen-presenting cell or the like. Alternatively, it may be a WT1 peptide which is restricted to the same type of an MHC class I molecule as that of a subject from which an antigen-presenting cell is derived.

The WT1 peptide of the present invention has an ability to bind to any one of an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule and HLA-DPB1*0501 molecule. Thus, the WT1 peptide may be a peptide which has an ability to bind to at least two of an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule and HLA-DPB1*0501 molecule, or a peptide that has an ability to bind to an HLA-DRB1*1501 molecule and/or HLA-DPB1*0901 molecule and/or HLA-DPB1*0501 molecule, and an HLA class II molecule other than the molecules, for example, a peptide which has an ability to bind to an HLA-DRB1*1501 molecule, HLA-DRB1*0405 molecule and/or HLA-DRB1*1502 molecule, a peptide which has an ability to bind to an HLA-DPB1*0901 molecule, HLA-DRB1*0405 molecule and/or HLA-DRB1*1502 molecule, a peptide which has an ability to bind to an HLA-DPB1*0501 molecule, HLA-DRB1*0405 molecule and/or HLA-DRB1*1502 molecule, or a peptide which has an ability to bind to an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule, HLA-DPB1*0501 molecule, HLA-DRB1*0405 molecule and/or HLA-DRB1*1502 molecule. Because a WT1 peptide having an amino acid sequence: Lys Arg Tyr Phe Lys Leu Ser His Leu Gln Met His Ser Arg Lys His (SEQ ID No: 2) has an ability to bind to an HLA-DRB1*1501 molecule, an HLA-DPB1*0901 molecule, an HLA-DPB1*0501 molecule, an HLA-DRB1*0405 molecule and an HLA-DRB1*1502 molecule, the WT1 peptide having such an amino acid sequence is preferable. In general, an MHC class II-binding peptide consists of 10-25 amino acids. Therefore, the WT1 peptide preferably has an amino acid sequence consisting of 10-25 amino acids.

The WT1 peptide of the present invention can be synthesized by methods generally used in the art or modifications thereof. Such methods are described, for example, in Peptide Synthesis, Interscience, New York, 1966; The Proteins, Vol 2, Academic Press Inc., New York, 1976; Peptide-Gosei, Maruzen Co., Ltd., 1975; Peptide-Gosei No Kiso To Jikken, Maruzen Co., Ltd., 1985; and Iyakuhin No Kaihatsu (Zoku), Vol. 14, Peptide-Gosei, Hirokawa—Book store, 1991.

The WT1 peptide of the present invention can also be prepared using genetic engineering techniques based on the information about the nucleotide sequence that encodes the WT1 peptide. Such genetic engineering techniques are well known to a person skilled in the art.

The antigen-presenting cell refers to a cell such as a dendritic cell which can present the WT1 peptide together with a MHC class II molecule to a helper T cell or the like. Thus, a subject from which the antigen-presenting cell is derived must have the same subclass of MHC class II (for example, HLA-DRB1*1501, HLA-DPB1*0901, HLA-DPB1*0501, HLA-DRB1*0405 or HLA-DRB1*1502) as that to which the added WT1 peptide binds.

In general, a helper T cell is activated by the recognition of an antigen peptide through an MHC class II molecule on the surface of an antigen-presenting cell by TCR-CD3 complex on the surface of the T cell, and the stimulation of an integrin on the surface of the T cell by an integrin ligand on the surface of the antigen-presenting cell. In the present invention, the activation of the helper T cell encompasses not only the activation of the helper T cell but also the induction and growth of the helper T cell. As described above, the activated helper T cell has a function to activate an immune system by increasing the induction, growth or activation of a B cell or T cell. Thus, the method for the activation of a helper T cell of the present invention can be used as an adjuvant therapy in the treatment of a cancer or the like. Alternatively, the helper T cell activated in vitro using the method of the present invention can be used to treat or prevent a cancer or the like, or can be used as an adjuvant therapy in the same. The activation of the helper T cell can be determined by measuring the amount of the production or secretion of a cytokine such as an interferon and an interleukin, and the like.

The addition of the WT1 peptide to the antigen-presenting cell may be practiced directly by the addition of the WT1 peptide, or indirectly by the addition of an expression vector comprising a polynucleotide encoding the WT1 peptide or the addition of a cell comprising the expression vector. The expression vector comprising the polynucleotide encoding the WT1 peptide, and the cell comprising the expression vector can be produced by the method well known to the person skilled in the art.

In another aspect, the present invention relates to a composition for activating a helper T cell by the addition of a WT1 peptide to an antigen-presenting cell, comprising the WT1 peptide, wherein the WT1 peptide has an ability to bind to any one of an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule and HLA-DPB1*0501 molecule. When the composition of the present invention is administered to an HLA-DRB1*1501, HLA-DPB1*0901 or HLA-DPB1*0501-positive subject, an immune system in the subject is activated by the activation of the helper T cell in the subject. The WT1 gene is expressed at high levels in various cancers and tumors including hematopoietic tumors such as leukemia, myelodysplastic syndrome, multiple myeloma or malignant lymphoma, and solid cancers such as gastric cancer, colon cancer, lung cancer, breast cancer, germ cell cancer, hepatic cancer, skin cancer, bladder cancer, prostate cancer, uterine cancer, cervical cancer or ovarian cancer. Therefore, the composition of the present invention can be used as an adjuvant therapy in the treatment or prevention of a cancer. Alternatively, the helper T cell activated using the composition of the present invention can be used, for example, as an adjuvant in the treatment of a cancer.

As described above, the WT1 peptide of the present invention may be a peptide which has an ability to bind to at least two of an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule and HLA-DPB1*0501 molecule, or a peptide which has an ability to bind to an HLA-DRB1*1501 molecule and/or HLA-DPB1*0901 molecule and/or HLA-DPB1*0501 molecule, and an MHC class II molecule other than them. Thus, as long as the antigen-presenting cell is derived from a subject positive for an MHC class II subclass to which the WT1 peptide of the present invention can bind, the effect of activating the helper T cell of the composition of the present invention can result.

The composition of the present invention may comprise in addition to the WT1 peptide, for example, a carrier, an excipient, an additive or the like. Because the WT1 peptide comprised in the composition of the present invention activate the helper peptide specifically to the WT1 peptide, the composition may comprise an MHC class I-restricted WT1 peptide, or it may be used with the peptide.

The method for using the composition of the present invention can be appropriately selected depending on conditions such as the desired activation of the helper T cell, the state of the antigen-presenting cell. Examples of such methods include, but are not limited to, intradermal administration, subcutaneous administration, intramuscular administration, intravenous administration, nasal administration and oral administration, and the addition to a culture medium of the antigen-presenting cell. The amount of the WT1 peptide comprised in the composition of the present invention, as well as the form, the number of times of use the like of the composition of the present invention can be appropriately selected depending on conditions such as the desired activation of the helper T cell, the state of the antigen-presenting cell.

In a further aspect, the present invention relates to a composition for activating a helper T cell by the addition of a WT1 peptide to an antigen-presenting cell, comprising an expression vector comprising a polynucleotide encoding the WT1 peptide or a cell comprising the expression vector, wherein the WT1 peptide has an ability to bind to any one of an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule and HLA-DPB1*0501 molecule. The expression vector comprising the polynucleotide encoding the WT1 peptide and the cell comprising the expression vector are described above.

In another aspect, the present invention relate to use of an expression vector comprising a polynucleotide encoding a WT1 peptide, or a cell comprising the expression vector for the manufacture of the composition.

In a further aspect, the present invention relates to a kit for activating a helper T cell by the addition of a WT1 peptide to an antigen-presenting cell, comprising the WT1 peptide, wherein the WT1 peptide has an ability to bind to any one of an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule and HLA-DPB1*0501 molecule. Preferably, the kit is used in the method for the activation of a helper T cell. The kit of the present invention may comprise in addition to the WT1 peptide, for example, a means of obtaining an antigen-presenting cell, a means to determine a helper T cell activity or the like. In general, an instruction manual is attached to the kit. By using the kit of the present invention, helper T cells can be induced efficiently.

In another aspect, the present invention relates to a kit for activating a helper T cell by the addition of a WT1 peptide to an antigen-presenting cell, comprising an expression vector comprising a polynucleotide encoding WT1 peptide, or a cell comprising the expression vector, wherein the WT1 peptide has an ability to bind to any one of an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule and HLA-DPB1*0501 molecule.

In another aspect, the present invention relates to a method for the treatment or prevention of a cancer in a subject, comprising adding a WT1 peptide to an antigen-presenting cell, and thereby activating a helper T cell, wherein the WT1 peptide has an ability to bind to any one of an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule and HLA-DPB1*0501 molecule. The method of the present invention is a method in which an immune system in the subject is activated by the activation of a helper T cell, and a cancer in the subject is treated or prevented. The addition of the WT1 peptide to the antigen-presenting cell may be practiced directly by the addition of the WT1 peptide, or indirectly by the addition of an expression vector comprising a polynucleotide encoding the WT1 peptide or the addition of a cell comprising the expression vector.

As described above, the helper T cell recognizes the complex of any one of MHC class II molecules, particularly an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule or HLA-DPB1*0501 molecule and the WT1 peptide. Therefore, the subject is a subject having an MHC class II molecule to which the WT1 peptide binds, for example, HLA-DRB1*1501-positive, HLA-DPB1*0901-positive or HLA-DPB1*0501-positive subject. As described above, the WT1 peptide of the present invention may be a peptide which has an ability to bind to at least two of an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule and HLA-DPB1*0501 molecule, or a peptide which has an ability to bind to an HLA-DRB1*1501 molecule and/or HLA-DPB1*0901 molecule and/or HLA-DPB1*0501 molecule, and an MHC class II molecule other than them. Thus, in such a case, it is possible to treat or prevent a cancer in a subject positive for an MHC class II subclass to which the WT1 peptide of the present invention can bind. The cancer to be treated or prevented may be any one, and examples thereof include hematopoietic tumors such as leukemia, myelodysplastic syndrome, multiple myeloma or malignant lymphoma, and solid cancers such as gastric cancer, colon cancer, lung cancer, breast cancer, germ cell cancer, hepatic cancer, skin cancer, bladder cancer, prostate cancer, uterine cancer, cervical cancer or ovarian cancer. Furthermore, the method of the present invention may be used with a method for the treatment or prevention of a cancer with an MHC class I molecule-restricted WT1 peptide or a pharmaceutical composition for the same.

In another aspect, the present invention relates to a pharmaceutical composition for the treatment or prevention of a cancer in a subject by activating a helper T cell by the addition of a WT1 peptide to an antigen-presenting cell, comprising the WT1 peptide, wherein the WT1 peptide has an ability to bind to any one of an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule and HLA-DPB1*0501 molecule. The WT1 gene is expressed at high levels in various cancers and tumors including hematopoietic tumors such as leukemia, myelodysplastic syndrome, multiple myeloma or malignant lymphoma, and solid cancers such as gastric cancer, colon cancer, lung cancer, breast cancer, germ cell cancer, hepatic cancer, skin cancer, bladder cancer, prostate cancer, uterine cancer, cervical cancer or ovarian cancer. Therefore, the pharmaceutical composition of the present invention can be used for the treatment or prevention of a cancer.

As described above, the WT1 peptide of the present invention may be a peptide which has an ability to bind to at least two of an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule and HLA-DPB1*0501 molecule, or a peptide which has an ability to bind to an HLA-DRB1*1501 molecule and/or HLA-DPB1*0901 molecule and/or HLA-DPB1*0501 molecule, and an MHC class II molecule other than them. Thus, as long as the antigen-presenting cell is derived from a subject positive for an MHC class II subclass to which the WT1 peptide of the present invention can bind, the pharmaceutical composition of the present invention can be used to treat or prevent a cancer.

When the pharmaceutical composition of the present invention is administered to, for example, an HLA-DRB1*1501-positive, HLA-DPB1*0901-positive or HLA-DPB1*0501-positive subject, an immune system in a subject can be activated by the activation of the helper T cell by the WT1 peptide comprised in the pharmaceutical composition, thereby treating or preventing a cancer. Thus, the pharmaceutical composition of the present invention may be used together with the method for the treatment or prevention of a cancer or the pharmaceutical composition for the same.

The pharmaceutical composition of the present invention may comprise in addition to the WT1 peptide as an active ingredient, for example, a carrier, an excipient or the like. The WT1 peptide comprised in the pharmaceutical composition of the present invention binds to an MHC class II molecule on the surface of an antigen-presenting cell and activates a helper T cell. Therefore, the pharmaceutical composition of the present invention may further comprise an activator, growth factor, inducer or the like of the helper T cell, or may comprise an MHC class I-restricted WT1 peptide.

The method for administering the pharmaceutical composition of the present invention can be appropriately selected depending on conditions such as the type of disease, the condition of the subject or target site. Examples of such methods include, but are not limited to, intradermal administration, subcutaneous administration, intramuscular administration, intravenous administration, nasal administration and oral administration. The amount of the peptide comprised in the pharmaceutical composition of the present invention, as well as the dosage form, the number of times of the administration and the like of the pharmaceutical composition of the present invention can be appropriately selected depending on conditions such as the type of disease, the condition of the subject or the target site. The single dose of the peptide is usually, 0.0001 mg-1000 mg, preferably, 0.001 mg-1000 mg.

In a further aspect, the present invention relates to a pharmaceutical composition for the treatment or prevention of a cancer in a subject by activating a helper T cell by the addition of a WT1 peptide to an antigen-presenting cell, comprising an expression vector comprising a polynucleotide encoding the WT1 peptide, or a cell comprising the expression vector, wherein the WT1 peptide has an ability to bind to any one of an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule and HLA-DPB1*0501 molecule.

In a further aspect, the present invention relates to use of a WT1 peptide, an expression vector comprising a polynucleotide encoding the WT1 peptide, or a cell comprising the expression vector for the manufacture of the pharmaceutical composition.

In another aspect, the present invention relates to an antibody binding specifically to a WT1 peptide, wherein the WT1 peptide has an ability to bind to any one of an HLA-DRB1*1501 molecule, an HLA-DPB1*0901 molecule and HLA-DPB1*0501 molecule. The antibody of the present invention can be prepared by the means or method known to the person skilled in the art. The antibody of the present invention can be used for the diagnosis of various cancers, prognosis thereof or the like.

In another aspect, the present invention relates to a method for the determination of the presence or amount of a WT1 peptide in an HLA-DRB1*1501-positive, HLA-DPB1*0901-positive or HLA-DPB1*0501-positive subject, comprising:

(a) reacting an anti-WT1 antibody with a sample form the subject; and

(b) determining the presence or amount of the anti-WT1 antibody binding specifically to the WT1 peptide contained in the sample. For example, it is possible to diagnose a cancer, prognosis thereof or the like by incubating the anti-WT1 antibody with a sample from an HLA-DRB1*1501-positive, HLA-DPB1*0901-positive or HLA-DPB1*0501-positive subject, or administering the anti-WT1 antibody to an HLA-DRB1*1501-positive, HLA-DPB1*0901-positive or HLA-DPB1*0501-positive subject, and determining, for example, the position, site or amount thereof. The anti-WT1 antibody of the present invention refers to an antibody which can specifically recognize the WT1 peptide of the present invention. The anti-WT1 antibody may be a monoclonal antibody or polyclonal antibody. The anti-WT1 antibody may be labeled. A known label such as a fluorescent label or a radioactive label can be used as a label. By labeling it, the presence or amount of the WT1 peptide can be determined readily and rapidly.

In another aspect, the present invention relates to a kit for the determination of the presence or amount of a WT1 peptide comprising the anti-WT1 antibody as an essential component.

Furthermore, in the determination of the presence or amount of the WT1 peptide, when the WT1 peptide has an ability to bind to an HLA-DRB1*0405 molecule and/or HLA-DRB1*1502 molecule, it is possible to determine the presence or amount of the WT1 peptide in a subject with such an MHC class II subclass.

In another aspect, the present invention relates to a pharmaceutical composition for the treatment or prevention of a cancer, comprising a helper T cell activated with a WT1 peptide, wherein the WT1 peptide has an ability to bind to an any one of an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule and HLA-DPB1*0501 molecule. The cancer is treated or prevented by the induction, growth or activation of a B cell or T cell by the activated helper T cell. Thus, the pharmaceutical composition of the present invention in this aspect may be used together with another method for the treatment or prevention of a cancer or pharmaceutical composition for the same. The activation of the helper T cell with the WT1 peptide encompasses not only the direct activation with the WT1 peptide but also indirect activation with an expression vector comprising a polynucleotide encoding the WT1 peptide or a cell comprising the expression vector.

The pharmaceutical composition of the present invention may comprise in addition to the activated helper T cell as an active ingredient, for example, a carrier, an excipient or the like. The method for administering the pharmaceutical composition of the present invention can be appropriately selected depending on conditions such as the type of disease, the condition of the subject or the target site. Examples of such methods include, but are not limited to, intradermal administration, subcutaneous administration, intramuscular administration, intravenous administration, nasal administration and oral administration. The amount of the helper T cell comprised in the pharmaceutical composition of the present invention, as well as the dosage form, the number of times of the administration and the like of the pharmaceutical composition of the present invention can be appropriately selected depending on a condition such as the type of disease, the condition of the subject or the target site.

In another aspect, the present invention relates to a method for the treatment or prevention of a cancer, comprising adding a WT1 peptide to an antigen-presenting cell, and thereby activating a helper T cell, and administering the activated helper T cell to a subject, wherein the WT1 peptide has an ability to bind to any one of an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule and HLA-DPB1*0501 molecule.

In another aspect, the present invention relates to use of a WT1 peptide for the manufacture of the pharmaceutical composition comprising an activated helper T cell.

In a further aspect, the present invention relates to a method for the determining the presence or amount of a WT1-specific helper T cell in any one of an HLA-DRB1*1501-positive, HLA-DPB1*0901-positive and HLA-DPB1*0501-positive subject, comprising:

(a) reacting a complex of a WT1 peptide and an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule or HLA-DPB1*0501 molecule with a sample from the subject; and

(b) determining the presence or amount of a helper T cell recognizing the complex contained in the sample. The sample from the subject may be any one as long as there is a possibility that it contains a lymphocyte. Examples of the samples include body fluid such as blood or lymph and a tissue. The complex of a WT1 peptide and an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule or HLA-DPB1*0501 molecule may be prepared, for example, as a tetramer or pentamer using a method known to a person skilled in the art such as biotin-streptavidin method. The presence or amount of the helper T cell recognizing such a complex can be measured by a method known to a person skilled in the art. In this aspect of the present invention, the complex may be labeled. A known label such as a fluorescent label or a radioactive label can be used as a label. By labeling it, the presence or amount of the helper T cell can be rapidly or readily determined. The method of the present invention in this aspect can be used to diagnose a cancer, prognosis thereof or the like.

Thus, the present invention also provides composition for the determination of the presence or amount of a helper T cell in any one of an HLA-DRB1*1501-positive, HLA-DPB1*0901-positive and HLA-DPB1*0501-positive subject, comprising a complex of a WT1 peptide and an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule or HLA-DPB1*0501 molecule.

Furthermore, the present invention provides a kit for the determination of the presence or amount of a helper T cell in an HLA-DRB1*1501-positive, HLA-DPB1*0901-positive or HLA-DPB1*0501-positive subject, comprising a complex of a WT1 peptide and an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule or HLA-DPB1*0501 molecule.

Furthermore, in the determination of the presence or amount of the helper T cell, when the WT1 peptide has an ability to an HLA-DRB1*0405 molecule and/or HLA-DRB1*1502 molecule in the determination of the presence or amount of the helper T cell, it is possible to determine the presence or amount of the helper T cell in a subject with such an MHC class II subclass. In such a case, a complex of a WT1 peptide and a MHC class II molecule to which the WT1 peptide binds is used.

In a further aspect, the present invention relates to a method for the obtainment of a helper T cell using a complex of a WT1 peptide and an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule or HLA-DPB1*0501 molecule, comprising:

(a) reacting a sample with the complex; and

(b) obtaining a helper T cell recognizing the complex contained in the sample. The complex is described above. The sample may be any one as long as there is a possibility that it contains a lymphocyte. Examples of the samples include a sample from a subject such as blood, and a cell culture. The helper T cell recognizing the complex can be obtained using a method known to a person skilled in the art such as FACS or MACS. The present invention allows to culture the obtained helper T cell and use it for the treatment or prevention of various cancers.

Thus, the present invention also relates to a helper T cell which is obtainable by a method for obtaining a helper T cell using a complex of a WT1 peptide and an HLA-DRB1*1501 molecule, HLA-DPB1*0901: molecule or HLA-DPB1*0501 molecule.

Furthermore, the present invention relates to a kit for obtaining a helper T cell, comprising a complex of a WT1 peptide and an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule or HLA-DPB1*0501 molecule.

Furthermore, in obtaining the helper T cell, when the WT1 peptide has an ability to bind to an HLA-DRB1*0405 molecule and/or HLA-DRB1*1502 molecule, it is possible to obtain a helper T cell recognizing a complex of such an MHC class II subclass and a WT1 peptide. In such a case, the complex of the WT1 peptide and an MHC class II molecule to which it binds is used.

In another aspect, the present invention relates to a method for the determination of the presence or amount of a WT1-specific helper T cell in an HLA-DRB1*1501-positive, HLA-DPB1*0901-positive, HLA-DPB1*0501-positive, HLA-DRB1*0405-positive or HLA-DRB1*1502-positive subject, comprising:

(a) stimulating a peripheral blood mononuclear cell, invasive lymphocyte, tumor cell, cell in ascitic fluid, cell in pleural fluid, cell in cerebrospinal fluid, bone marrow cell or lymph node cell with a WT1 peptide; and

(b) determining the production of a cytokine or the reaction of the helper T cell,

wherein a presence or an increase in the amount of the production of the cytokine or the reaction of the helper T cell indicates the presence or amount of the WT1-specific helper T cell. The cells such as the peripheral blood mononuclear cell, invasive lymphocyte, tumor cell, cell in ascitic fluid, cell in pleural fluid, cell in cerebrospinal fluid, bone marrow cell and lymph node cell used in the method of the present invention may be derived from a healthy subject or a cancer patient. By using the cells from a healthy subject, it is possible to determine whether or not the subject is suffering from a cancer, whether or not the subject has the predisposition thereof or the like. By using the cells from a cancer patient, it is possible to predict whether or not WT1-immunnotherapy has a effect on the cancer patient or the like. The stimulation of the cells with the WT1 peptide may be practiced in vitro or in vivo. Because of easiness, in vitro stimulation is preferable. The presence of the production of the cytokine or the reaction of the helper T cell, or the amount of the production of the cytokine or the reaction of the helper T cell can be determined by a known method.

The following examples illustrate the present invention in more detail, but are not to be construed to limit the scope thereof.

Examples

1. Preparation of Antigen-Presenting Cell

Peripheral blood mononuclear cells (PBMCs) were separated from peripheral blood that had been collected from a healthy donor (HLA-DRB1*1501-positive, HLA-DPB1*0901-positive or HLA-DPB1*0501-positive). The PBMCs were seeded to a 6-well plastic plate at the density of 1×10⁷ cells/well in 1% AB serum (Nabi, Miami, Fla.), X-VIVO 15 medium (Cambrex), and cultured for 2 hours. After the culture, suspension cells were removed, and the remaining adherent cells were cultured in 1000 IU/ml IL-4 (PeproTech), 1000 IU/ml GM-CSF (PeproTech), 1% AB serum and X-VIVO 15 medium. On day 2 and day 4, the medium was changed, and IL-4 and GM-CSF were added. On day 6, 100 IU/ml TNF-α was added to mature antigen-presenting cells.

2. Induction of WT1 Peptide-Specific CD4-Positive T Cell

CD4-positive T cells were separated from blood derived from the same donor using RosetteSep for the separation of CD4-positive T cells (StemCell). The CD4-positive T cells (3×10⁶ cells) were added to each well of a 24-well plate. They were stimulated with autologous antigen-presenting cells (3×10⁵ cells) that had been pulsed with 20 μg/ml WT1 peptide (SEQ ID No: 2), and irradiated with 25 Gy of radiation. On next day after the stimulation, 20 IU/ml IL-2 was added. Likewise, the stimulated CD4-positive T cells were stimulated using the antigen-presenting cells pulsed with 20 μg/ml WT1 peptide every other week. Furthermore, the medium was changed to the medium containing IL-2 every other day after second stimulation. The CD4-positive T cells induced by total three times of stimulation (HLA-DRB1*1501 and HLA-DPB1*0901-positive T cells were defined as TA28.1 cell and E15.2 cell, respectively) were used for experiments below.

3. Measurement of IFN-γ

TA28.1 cells and peripheral blood mononuclear cells from a subject from which the TA28.1 cells were derived were cultured in the presence of 20 μg/ml WT1 peptide for 24 hours. After the culture, the amount of IFN-γ in the supernatant was quantified using ELISA kit. As a control, a peripheral blood mononuclear cell from an HLA-DRB1*1501-negative subject was used. The results are shown in FIG. 1. It was confirmed that TA28.1 cell recognizes the WT1 peptide specifically to an HLA-DRB1*1501 molecule to increase the produced amount of IFN-γ (that is, activation).

Furthermore, it was confirmed that TA28.1 cell and E15.2 cell do not produce IL-4 and IL-10 using ELISA kit. The results are shown in FIGS. 2 and 3. It was confirmed that TA28.1 and E15.2 cell are Th1 cells.

HLA-DPB1*0501/*0501-positive mononuclear were used to perform the following experiments. The cells were suspended to X-VIVO (1% AB serum), and 20 pg/ml WT1 peptide, 10 pg/ml Brefeldin A and 0.5 pg/ml CD28/49d were added. They were incubated at 37° C. with 5% CO₂ for 4 hours. Ad a control, a cell incubated without the addition of a WT1 peptide was used. After washing with buffer, an anti-CD3-perCP antibody and an anti-CD4-APC antibody were added, and they were incubated at 4° C. for 30 minutes. After washing with buffer, the cells were fixed and permeabilized using a fixation and permeabilization kit BD CYTOFIX/CYTOPERM™ (4° C., 20 minutes). After washing with BD perm/wash buffer, an anti-INF-γ-FITC (BD, clone: B27) and anti-IL-17-PE (eBioscience, clone: eBio64DEC17) were added, and they were incubated at 4° C. for 30 minutes. After washing with buffer, cells were analyzed with FACSAria. The results are shown in FIG. 4. It was confirmed that an HLA-DPB1*0501-positive mononuclear cells grow, and produces IFN-γ and IL-17.

4. Growth Assay

The growth assay was performed by [³H]-thymidine incorporation method. TA28.1 cells (3×10⁴ cells) and peripheral blood mononuclear cells (HLA-DRB1*1501-positive; 1×10⁵ cells) that had been pulsed with the WT1 peptides and irradiated were cocultured in a 96-well plate. After coculturing for 80 hours, 37 kBq/well [³H]-thymidine (Amersham Biosciences) was added. They were incubated for another 16 hours, and measured using β-scintillation counter. The measurements were represented as count/minute (cpm). As a control, a peripheral blood mononuclear cell without pulsing with a peptide was used. Furthermore, in order to confirm that the activation signal is specific for an HLA-DRB1*1501 molecule, an anti-MHC class I antibody, anti-HLA-DR antibody, anti-HLA-DQ antibody and anti-HLA-DP antibody were used. The results are shown in FIG. 5. It was confirmed that TA28.1 cells were activated by a signal through the WT1 peptide and HLA-DRB1*1501, and grown. It was further confirmed that the growth was specific for HLA-DRB1*1501, because it was suppressed by the anti-HLA-DR antibody.

Likewise, E15.2 cells were used to perform the growth assay. As an additional control, the peripheral blood mononuclear cells from an HLA-DPB1*0901-negative subject were used. The results are shown in FIGS. 6 and 7. It was confirmed that E15.2 cells were activated by a signal through the WT1 peptide and HLA-DPB1*0901, and grown. It was further confirmed that the growth is specific for HLA-DPB1*0901, because it is suppressed by the anti-HLA-DP antibody.

Furthermore, HLA-DPB1*0501/*0501-positive mononuclear cells were used to perform the growth assay. As a control, a peripheral blood mononuclear cell from an HLA-DPB1*0501-negative subject was also used. The results are shown in FIGS. 8 and 9. It was confirmed that an HLA-DPB1*0501/*0501-positive mononuclear cells were activated by a signal through the WT1 peptide and HLA-DPB1*0501, and grown. It was further confirmed that the growth is specific for HLA-DPB1*0501, because it is suppressed by the anti-HLA-DP antibody.

Furthermore, the growth assay of the E15.2 cells was performed with various concentrations of the WT1 peptide. The concentration of the used WT1 peptide was 0.08, 0.4, 2, 10, 50, 100 or 150 μg/ml. The results are shown in FIG. 10. It was confirmed that the WT1 peptides grow the E15.2 cells in a concentration-dependent manner.

INDUSTRIAL APPLICABILITY

The present invention provides a method for the activation of a helper T cell with a WT1 peptide which has an ability to bind to an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule or HLA-DPB1*0501 molecule and a composition for the same, as well as a pharmaceutical composition for the treatment and/or prevention of a cancer by activating a helper T cell and the like. Therefore, the present invention can be used in the fields of medicine and the like, for example, in the fields of development and preparation of a pharmaceutical composition for the prevention or treatment of various hematopoietic tumors and solid cancers that express WT1 gene at high levels. 

The invention claimed is:
 1. A method for activating a helper T cell, comprising contacting an antigen-presenting cell with a WT1 peptide, and thereby activating the helper T cell, wherein: (a) the WT1 peptide has an ability to bind to an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule, and HLA-DPB1*0501 molecule, and wherein the WT1 peptide is a peptide consisting of amino acid sequence: Lys Arg Tyr Phe Lys Leu Ser His Leu Gln Met His Ser Arg Lys His (SEQ ID NO: 2); and (b) the antigen-presenting cell is positive for at least one molecule chosen from HLA-DRB1*1501, HLA-DPB1*0901, and HLA-DPB1*0501; and (c) the helper T cell expresses a TCR-CD3 complex that recognizes a complex of a WT1 peptide and an HLA-molecule chosen from HLA-DRB1*1501, HLA-DPB1*0901, and HLA-DPB1*0501.
 2. The method of claim 1, wherein the WT1 peptide further has an ability to bind to an HLA-DRB1*0405 molecule and/or HLA-DRB1*1502 molecule.
 3. The method of claim 1, wherein the step of contacting the antigen presenting cell with the WT1 peptide is practiced by adding to the antigen presenting cell the WT1 peptide.
 4. A method for producing an immune response in a subject having a WT1-specific cancer, comprising contacting an antigen-presenting cell with a WT1 peptide, and thereby activating a helper T cell of the subject, wherein (a) the WT1 peptide has an ability to bind to an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule, and HLA-DPB1*0501 molecule, and wherein the WT1 peptide is a peptide consisting of amino acid sequence: Lys Arg Tyr Phe Lys Leu Ser His Leu Gln Met His Ser Arg Lys His (SEQ ID NO: 2); and (b) the antigen-presenting cell is positive for at least one molecule chosen from HLA-DRB1*1501, HLA-DPB1*0901, and HLA-DPB1*0501; and (c) the helper T cell expresses a TCR-CD3 complex that recognizes a complex of a WT1 peptide and an HLA-molecule chosen from HLA-DRB1*1501, HLA-DPB1*0901, and HLA-DPB1*0501.
 5. The method of claim 4, wherein the WT1 peptide further has an ability to bind to an HLA-DRB1*0405 molecule and/or HLA-DRB1*1502 molecule.
 6. The method of claim 4, wherein the step of contacting the antigen presenting cell with the WT1 peptide is practiced by adding to the antigen presenting cell the WT1 peptide.
 7. The method of claim 4, wherein the WT1-specific cancer is a hematopoietic tumor or a solid cancer.
 8. The method of claim 7, wherein the hematopoietic tumor is leukemia, myelodysplastic syndrome, multiple myeloma, or malignant lymphoma.
 9. The method of claim 7, wherein the solid cancer is gastric cancer, colon cancer, lung cancer, breast cancer, germ cell cancer, hepatic cancer, skin cancer, bladder cancer, prostate cancer, uterine cancer, cervical cancer, or ovarian cancer.
 10. A method for producing an immune response in a subject having a WT1-specific cancer, comprising contacting an antigen presenting cell with a WT1 peptide, thereby activating a helper T cell, and administering the activated helper T cell to the subject, wherein: (a) the WT1 peptide has an ability to bind to an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule, and HLA-DPB1*0501 molecule, and wherein the WT1 peptide is a peptide consisting of amino acid sequence: Lys Arg Tyr Phe Lys Leu Ser His Leu Gln Met His Ser Arg Lys His (SEQ ID NO: 2); and (b) the antigen-presenting cell is positive for at least one molecule chosen from HLA-DRB1*1501, HLA-DPB1*0901, and HLA-DPB1*0501; and (c) the helper T cell expresses a TCR-CD3 complex that recognizes a complex of a WT1 peptide and an HLA-molecule chosen from HLA-DRB1*1501, HLA-DPB1*0901, and HLA-DPB1*0501.
 11. The method of claim 10, wherein the WT1 peptide further has an ability to bind to an HLA-DRB1*0405 molecule and/or HLA-DRB1*1502 molecule.
 12. The method of claim 10, wherein the WT1-specific cancer is a hematopoietic tumor or a solid cancer.
 13. The method of claim 12, wherein the hematopoietic tumor is leukemia, myelodysplastic syndrome, multiple myeloma, or malignant lymphoma.
 14. The method of claim 12, wherein the solid cancer is gastric cancer, colon cancer, lung cancer, breast cancer, germ cell cancer, hepatic cancer, skin cancer, bladder cancer, prostate cancer, uterine cancer, cervical cancer, or ovarian cancer.
 15. A method comprising administering a peptide to a subject who has been diagnosed with a WT1-specific cancer, wherein: (a) the WT1 peptide has an ability to bind to an HLA-DRB1*1501 molecule, HLA-DPB1*0901 molecule, and HLA-DPB1*0501 molecule, and wherein the WT1 peptide is a peptide consisting of amino acid sequence: Lys Arg Tyr Phe Lys Leu Ser His Leu Gln Met His Ser Arg Lys His (SEQ ID NO: 2); and (b) the subject has an HLA-molecule chosen from HLA-DRB1*1501, HLA-DPB1*0901, and HLA-DPB1*0501.
 16. The method of claim 15, wherein the WT1 peptide further has an ability to bind to an HLA-DRB1*0405 molecule and/or HLA-DRB1*1502 molecule.
 17. The method of claim 15, wherein the WT1-specific cancer is a hematopoietic tumor or a solid cancer.
 18. The method of claim 17, wherein the hematopoietic tumor is leukemia, myelodysplastic syndrome, multiple myeloma, or malignant lymphoma.
 19. The method of claim 17, wherein the solid cancer is gastric cancer, colon cancer, lung cancer, breast cancer, germ cell cancer, hepatic cancer, skin cancer, bladder cancer, prostate cancer, uterine cancer, cervical cancer, or ovarian cancer. 